Table 1.

Mode of nanoparticle application influences phytotoxicity and their physiological function

Type of NPs	Conc. of NPs	Mode of NPs application	Physiological function	Phyto-toxicity	Condition	Reference
Silver nanoparticles (AgNPs)
AgNPs	5 and 10 mg/L	Seed priming	Improved Water Intake, Seed Germination and starch Metabolism	Elevated ROS and H2O2	Normal	[28]
AgNPs	100 and 1000 mg/L	Seed priming	Decreased the germination and growth of rice seedlings	–	Normal	[36]
AgNPs	60 mg/L	Seed priming	Improved agro-morphological parameters, biochemical parameters, and enzymatic activities	–	Normal	[36]
AgNPs	150 mg/L	Soil	Increase of antioxidants, lipid peroxidation, and reduced contents of chlorophyll, carotenoids, total carbohydrate, and total soluble proteins	Accumulation of AgNPs in root > leaf > stem	Normal	[36]
AgNPs	200 mg/L	Vegetative growth stage	Increase of antioxidants, lipid peroxidation, and reduced contents of chlorophyll, carotenoids, total carbohydrate, and total soluble proteins	Accumulation of AgNPs in root > leaf > stem	Normal	[37]
AgNPs	10 and 15 mg/L	Seed priming and foliar application	Higher germination rate, increased chlorophyll contents, increased stomatal conductance, and higher seedling masses	Reduced diseased condition in seeds	Thermal stress	[38]
Gold nanoparticles (AuNPs)
AuNPs	500–1000 µM and 5–11 mg/L	Soil	Increased the seed germination and vegetative growth	–	Normal	[44]
AuNPs	5–11 mg/L	Soil	Increased seed germination rate	–	Normal	[44]
AuNPs	5 to 15 ppm	Seed priming	Enhanced germination of naturally aged seeds, improved overall growth	–	Normal	[38]
AuNPs	10, 25, 50 and 100 mg/L	Foliar spray	10 ppm increased the number of leaves per plant and seed yield and 25 ppm increased total sugar content	–	Normal	[45]
AuNPs	20 µg/mL	Seed priming	Defense mechanism by improving plant growth and photosynthesis	–	Cold stress	[45]
AuNPs	0.1–10 mg/L	Size dependent (15, 30 and 40 nm)	Increase in chromosomal aberrations and decrease in mitotic index	–	Normal	[47]
AuNPs	10 mg/L	Size dependent (10 nm)	Decreased biomass and root length	–	Normal	[48]
AuNPs	22–25 nm	Hydroponic or soil mixing methods	-	Dose-dependent DNA damage	Normal	[49]
AuNPs	3.5 nm	Spherical-shaped AuNPs	Transporting in size-dependent mechanisms and translocating to cells and tissues	Exhibited leaf necrosis	Normal	[50]
Zinc nanoparticles (ZnONPs)
ZnONPs	500 mg/mL	Soil	Improving the growth, chlorophyll contents, Zn contents	Reducing oxidative stress and cadmium (Cd) contents	Cd stress	[51]
ZnONPs	200 mg/mL	Foliar spray	Improving the growth, chlorophyll contents, Zn contents	Reducing oxidative stress and cadmium (Cd) contents	Cd stress	[51]
ZnONPs	1600 mg/L	Seed priming	Alfalfa was reduced to 40%, and tomato seeds by 20%, but increased cucumber seed germination	–	Normal	[53]
ZnONPs	100 mg/L	Seed	Increased germination rate	–	Normal	[54]
ZnONPs	1000 mg/L	Foliar application	Positive effect on plant height, stem diameter, chlorophyll content, fruit yield and biomass production	–	Normal	[51, 55–57]
ZnONPs	2000 mg/L	Foliar application	Negative effect on plant height, stem diameter, chlorophyll content, fruit yield and biomass production	Increase antioxidant activity	Normal	[51, 55–57]
ZnONPs	60 mg/L	Seed Priming	Maintain redox homeostasis by decreasing ROS generation; Increase antioxidant enzyme activities (SOD, peroxidase) and Low levels of Zn cannot elevate ROS due to poor activation of antioxidant machinery under stress conditions	Preventing cells from ROS attack under salt stress conditions	Salt stress	[58, 59]
ZnONPs	90 mg/L	Soil	Triggered localization of ZnONPs in vacuoles and chloroplasts; Reversed abnormal modifications to chloroplast, mitochondria, and cell wall	Stimulated antioxidant enzymes, enhanced osmolyte contents; No phytotoxicity observed under heat stress for alfalfa plants	Heat stress	[58, 59]
ZnONPs	100 mg/L	Foliar application	Improved drought-associated detrimental effects and growth-promoting effect	–	Normal and drought	[58, 59]
ZnONPs	400 mg/L	Foliar application	Increased oxidative stress	–	Normal	[60]
ZnONPs	400 mg/L	Foliar Application with Silicon Modification	Improved stability, hydrophilicity, and salt tolerance	–	Normal	[60]
ZnONPs	500 mg/L	Soil mixture	Increased Zn in roots; Root elongation; Translocation of Zn to aerial parts	Increased H2O2 accumulation in leaves; Reduced antioxidant enzymes (CAT, APX)	Normal	[61]
Copper nanoparticles (CuNPs)
CuNPs	4.44 mg/L	seed priming	Improved plant biomass in normal and drought conditions	–	Normal and drought	[61]
CuNPs	250 mg/L	Seed priming	Increased bioactive components (vitamin C, lycopene, total phenols, flavonoids), antioxidant enzyme accumulation (CAT, SOD)	–	Normal and drought	[62]
Cu	0–20 mg/L	Hydroponic Culture	Reduced root length in lettuce and alfalfa; Translocation of nCu observed in dose-dependent manner	Alfalfa more sensitive to nCu compared to lettuce	Normal	[71]
nCu	10 and 20 mg/L	Hydroponic Culture	Reduced water content, root length, dry biomass; Modified defense-related metabolites	–	Normal	[6, 70]
Cu@CuO and nCuSO4.5H2O	10 and 20 mg/L	Hydroponic Culture	Reduced water content, root length, dry biomass; Modified defense-related metabolites	–	Normal	[6, 70]
nCu(OH)2-b	1050 mg/L to 2100 mg/L	Foliar spray	Increased leaf biomass; Changes in metabolites indicating defensive response	–	Normal	[71]
nCu/Kg	200–800 mg/mL	Soil	Increased Cu accumulation in roots; Detrimental effects in stem, leaves, and fruits	–	Normal	[71]
nCu(OH)2-b	10 mg/L	Soil	Arrested photosynthesis, stunted growth in Clarika unguiculata	High light levels and limited soil conditions	Normal	[71]